Method and system for communication between a vehicle and a charging station for unlocking mechanical charging cable coupling

ABSTRACT

A method for communicating between an electric vehicle and a charging station for electrically charging at least one energy storage device of the electric vehicle. The electric vehicle is connected to the charging station during the charging process by a lockable mechanical coupling between a terminal of charging cable connected to the vehicle and a terminal of the charging station. Charging current is fed from the charging station through the charging cable. Information is transferred in the course of the charging process based on a communication between the electric vehicle and the charging station. The information includes a signal transmitted from the electric vehicle to the charging station for locking and/or unlocking the mechanical coupling. The signal triggers the locking and/or unlocking of the mechanical coupling between the terminal of the charging cable and the terminal at the charging station.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending application Ser. No.15/582,971, filed May 1, 2017, which was a continuation of applicationSer. No. 14/580,666, filed Dec. 23, 2014, which was a divisional ofapplication Ser. No. 13/384,369, filed Jan. 17, 2012, which was a § 371national stage of international patent application PCT/EP2010/059435,filed Jul. 2, 2010, which designated the United States; this applicationalso claims the priority, under 35 U.S.C. § 119, of German patentapplications Nos. 10 2010 011 162, filed Mar. 12, 2010, and 10 2009 033305, filed Jul. 15, 2009; the prior applications are herewithincorporated by reference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a method for communicating between an electricvehicle and a charging station for electrically charging at least oneenergy storage device of the electric vehicle and to a correspondingcommunication system and to an electric vehicle and to an electricalcharging station.

The electrical energy storage devices of electric vehicle can nowadaysbe recharged at charging stations provided for this purpose. For this,the vehicle user connects his vehicle via a charging cable to thecharging station and initializes the charging operation in a suitablemanner, for example by means of authentication using a code at thecharging station. Over the course of the charging operation, informationrelating to the charging operation is transmitted in the process via oneor more communication channels between the vehicle and the chargingstation.

In order to avoid unauthorized removal of the charging cable from thecharging station during the charging operation, it is known to equip theterminal of the charging cable which is connected to a correspondingterminal of the charging station during charging with a lockingapparatus, which locks the terminal of the charging cable at thecharging station by means of a key or by means of a numerical code beinginput. This type of locking has proven impracticable for extensive useof electric vehicles, however, since keys or numerical codescorresponding to a large number of users, possibly also for differentoperators of charging stations, need to be issued for this purpose. Theobject of the invention is therefore to provide a simple possible way oflocking or unlocking the terminal of the charging cable at a terminal ofthe charging station during the charging operation of an electricvehicle at a charging station.

SUMMARY OF THE INVENTION

This object is achieved by the method as claimed or the system asclaimed or the charging station as claimed. Developments of theinvention are defined in the dependent claims.

In the method according to the invention for communicating between anelectric vehicle and a charging station, the electric vehicle isconnected, during the charging operation, to the charging station via alockable mechanical coupling between a terminal of a charging cableconnected to the electric vehicle and a terminal of the charging stationin order to supply charging current from the charging station, via thecharging cable, to at least one electrical energy storage device of theelectric vehicle. Over the course of the charging operation, informationis transmitted on the basis of a communication between the electricvehicle and the charging station. The term “over the course of thecharging operation” has a broad interpretation in this context and inparticular includes the transmission of information during and/or priorto and/or after a charging operation, for example for initiating orending the charging operation.

The method according to the invention is characterized by the fact thatthe transmitted information includes a signal transmitted from theelectric vehicle to the charging station for unlocking the mechanicalcoupling, with the unlocking of the mechanical coupling between theterminal of the charging cable and the terminal of the charging stationbeing triggered via the signal in the charging station.

By virtue of the method according to the invention, remote locking orremote unlocking of the terminal of the charging cable at acorresponding terminal of the charging station is achieved in a suitablemanner via the electric vehicle. This locking or unlocking is broughtabout via a communication between the vehicle and the charging station,with the result that it is not necessary according to the invention toimplement locking or unlocking directly at the charging station by meansof a corresponding key or numerical code.

According to the invention, the signal for unlocking or locking themechanical coupling can be performed in various ways, in particularsignals or signal sequences which are already known can be used for thesignal and are now interpreted in the charging station such that lockingor unlocking of the terminal of the charging cable at the chargingstation is achieved thereby. However, it is also possible for separatecontrol signals intended exclusively for the operation of locking orunlocking to be transmitted from the vehicle to the charging station forlocking or unlocking in order to trigger the locking or unlocking there.

The lockable mechanical coupling between the terminal of the chargingcable and the terminal of the charging station can have any desiredconfiguration. In a preferred variant, this coupling is a plug-typeconnection, in which a plug of the charging cable is plugged into acorresponding socket in the charging station. Locking can thus bebrought about by a suitable locking apparatus, for example via one ormore pins engaging in corresponding slots. Locking is in this casegenerally understood to mean fastening of the terminal of the chargingcable at the terminal of the charging station such that an unauthorizeduser cannot disconnect these terminals from one another, or can only doso with force.

In a particularly preferred embodiment of the method according to theinvention, the signal for locking and/or unlocking the mechanicalcoupling is coupled to a signal relating to the charging operationand/or state of charge of the at least one energy storage device of theelectric vehicle, in particular to a signal relating to the start and/orend of the charging operation and/or relating to application and/orsafety-disconnection of a voltage on the charging cable by the chargingstation. As an alternative or in addition, however, there is also thepossibility of the signal for locking and/or unlocking the mechanicalcoupling being configured in such a way that it is decoupled from asignal relating to the charging operation and/or state of charge of theat least one energy storage device of the electric vehicle.

One or more communication connections with any desired configuration canbe used for communication between the electric vehicle and the chargingstation. In particular, communication connections which are alreadyknown from the prior art can also be used. In a preferred variant, thesignal for locking and/or unlocking the mechanical coupling istransmitted via at least one of the following communication connections:

-   -   a PLC (power line communication) communication connection via        one or more lines of the charging cable which may also be able        to conduct current;    -   a monitoring connection which is isolated from the        current-conducting lines in the charging cable, such as via the        pilot pin described further below, for example, which is used to        provide a communication path parallel to the current-conducting        lines in the charging cable;    -   a communication connection, which is separate from the charging        cable, such as by means of radio transmission based on WLAN,        Bluetooth or the like, for example.

When using a communication connection which is separate from thecharging cable or in the case of the PLC communication connection, datatransmission is preferably performed on a packet basis. Accordingly, thetransmission of information via the monitoring connection which isseparate from the current-conducting lines in the charging cable ispreferably performed by means of pulse-width modulation and amplitudemodulation. In a particularly preferred embodiment of the signal forlocking or unlocking the mechanical coupling via the monitoringconnection, a plurality of states of the electric vehicle are indicatedto the charging station via this monitoring connection, with the statesincluding a first state, which indicates that the electric vehicle isready for charging at least one of its energy storage devices, and asecond state, which indicates that the at least one energy storagedevice of the electric vehicle is being charged via the charging cable,with a change between the first and second states representing a signalvia which the locking of the mechanical coupling between the terminal ofthe charging cable and the terminal of the charging station istriggered, and a change from the second state into the first staterepresenting a signal via which the unlocking of the mechanical couplingbetween the terminal of the charging cable and the terminal of thecharging station is triggered. The first and second states can in thiscase possibly also be signaled using methods already known from theprior art. In particular, the first or second state can represent the“ready for charging” and “charging” states, respectively, which aredefined in the standard ISO/IEC 61851, Part 1, still in development, andin the standard SAE J1772, already concluded. These standards regulatethe communication between an electric vehicle and a charging station.

In order to avoid unauthorized locking or unlocking of the mechanicalcoupling, in a preferred embodiment of the method according to theinvention, over the course of the communication between the electricvehicle and the charging station, authentication of the electric vehiclewith respect to the charging station is performed, the signal forlocking and/or unlocking the mechanical coupling being transmitted fromthe electric vehicle to the charging station only when authentication issuccessful. In a particularly preferred embodiment of the variants justdescribed, authentication data for performing the authentication aretransmitted via the above-described monitoring connection in thecharging cable, and then the authentication is performed via the PLCcommunication connection in the charging cable and/or the communicationconnection which is isolated from the charging cable. The authenticationdata can in this case in particular include identification of thevehicle and/or of the vehicle user or corresponding digital keys and/orcertificates, which are then used for authentication.

According to the invention, the signal for locking and/or unlocking themechanical coupling can be triggered in various ways from the vehicle.For example, the signal can be performed in response to the actuation ofthe central locking of the vehicle. In particular, when the vehicle islocked by means of the central locking, the locking of the mechanicalcoupling is triggered and, when the vehicle is opened via the centrallocking, the unlocking of the mechanical coupling is triggered. It islikewise possible for the signal for locking and/or unlocking themechanical coupling to be performed in response to the actuation of aswitch in the electric vehicle by a user.

In addition to the above-described method, the invention also relates toa system for communicating between an electric vehicle and a chargingstation for electrically charging at least one energy storage device ofthe electric vehicle, the electric vehicle being connected, during thecharging operation, between a terminal of a charging cable connected tothe electric vehicle and a terminal of the charging station via alockable mechanical coupling in order to supply charging current fromthe charging station via the charging cable to the at least one energystorage device. In this case, the system comprises a first communicationcontrol unit provided for the electric vehicle and a secondcommunication control unit provided for the charging station, withinformation being transmitted via the first and second communicationcontrol units during operation of the system over the course of thecharging operation on the basis of a communication between the electricvehicle and the charging station. The first and second communicationcontrol units are in this case configured such that the informationtransmitted includes a signal for locking and/or unlocking themechanical coupling generated by the first communication control unit,with locking and/or unlocking of the mechanical coupling between theterminal of the charging cable and the terminal of the charging stationbeing triggered by the second communication control unit via the signal.

The above-described system is preferably configured such that one ormore variants of the method according to the invention can beimplemented using the system.

The invention also relates to an electric vehicle for use in theabove-described method according to the invention, comprising at leastone energy storage device, it being possible for the electric vehicle tobe connected, during the charging operation, to a charging station forelectrically charging the at least one energy storage device via alockable mechanical coupling between a terminal of a charging cableconnected to the electric vehicle and a terminal of the charging stationin order to supply charging current from the charging station, via thecharging cable, to the at least one energy storage device, with it beingpossible for information to be transmitted to the charging station overthe course of the charging operation on the basis of a communicationbetween the electric vehicle and the charging station from acommunication control unit of the electric vehicle. The communicationcontrol unit is in this case configured such that it can transmit apredetermined signal, intended exclusively for locking and/or unlockingthe mechanical coupling, to the charging station in order to triggerlocking and/or unlocking of the mechanical coupling between the terminalof the charging cable and the terminal of the charging station in thecharging station. As has already been described above, the predeterminedsignal can be transmitted by the communication control unit, for exampleon actuation of the central locking of the electric vehicle and/or aswitch in the electric vehicle.

Furthermore, the invention relates to a charging station for use in theabove-described method according to the invention. In this case, thecharging station is used for electrically charging at least one energystorage device of an electric vehicle, with the electric vehicle beingconnected, during the charging operation, to the charging station via alockable mechanical coupling between a terminal of a charging cableconnected to the electric vehicle and a terminal of the charging stationin order to supply charging current from the charging station, via thecharging cable, to the at least one energy storage device. In this case,the charging station comprises a communication control unit, to whichinformation can be transmitted over the course of the charging operationon the basis of a communication between the electric vehicle and thecharging station. The communication control unit is in this caseconfigured in such a way that it triggers locking and/or unlocking ofthe mechanical coupling between the terminal of the charging cable andthe terminal of the charging station on reception of a predeterminedsignal transmitted from the electric vehicle to the charging station.

Exemplary embodiments of the invention will be described in detail belowwith reference to the attached drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 shows a schematic illustration of the communication between acharging station and an electric vehicle and further components, with itbeing possible for the method according to the invention to be used forthe communication between the charging station and the vehicle;

FIG. 2 shows a schematic illustration of the design of the plug of acharging cable for connection to a charging station, it being possiblefor the plug to be locked in the charging station with the aid of themethod according to the invention; and

FIG. 3 shows an illustration of a communication between a communicationcontrol unit in an electric vehicle and a communication control unit ina charging station for illustrating possible variants of the methodaccording to the invention.

DETAILED DESCRIPTION OF THE INVENTION

In order to implement an infrastructure for charging the batteries of anelectric vehicle, the standard ISO/IEC 61851 and ISO/IEC 15118 is beingdeveloped at present and is intended to regulate the communicationbetween an electric vehicle and a corresponding charging station forelectrically charging the battery of the vehicle. The followingembodiments are described with reference to this standard. FIG. 1illustrates schematically the communication between an electric vehicle1 and a corresponding charging station 2, with it being possible for thecharging station 2 to also communication with further logic components.As shown in FIG. 1, the electric vehicle 1 comprises a battery 1 a and acommunication control unit CC. This communication control unit CCcommunicates with a corresponding communication control unit CC′ withina charging station or a charging column 2. The communication between thecontrol units CC and CC′ is illustrated schematically by the continuousline K. This communication needs to be completely standardized inaccordance with the families of standards ISO/IEC 61851 and ISO/IEC15118.

As shown in FIG. 1, the vehicle is connected to a corresponding socket 5of the charging column 2 via a plug 3 of a charging cable 4. Inaccordance with the scenario illustrated, a driver wishing to charge thebattery 1 a of his electric vehicle 1 has plugged the vehicle onto thecharging column 2 via the charging cable 4 in order to supply chargingcurrent in this way via the charging cable to the battery 1 a. Over thecourse of the charging operation, the communication K takes placebetween the vehicle 1 and the charging station 2, with it being possiblefor the communication to take place via various communication paths, aswill be explained in more detail further below.

In order to provide the current drawn by the vehicle to the vehicleowner in a suitable manner and to charge the vehicle owner for thiscurrent, further components are also provided, as shown in FIG. 1. Theelectrical energy is provided to the charging column 2 via a gridoperator GO, with the grid operator drawing the energy from anelectricity supplier or power provider ES. The energy drawn from thecharging station 2 is in this case detected by an electricity meter EMwithin the charging station. The cost of the energy required forcharging the battery of the vehicle 1 is calculated via a costcalculation station CH in a suitable manner, with the cost calculationstation communicating with the communication control unit CC′ of thecharging station 2 for this purpose, as is indicated by the dashed arrowK′. This communication K′ is regulated on a message plane by thestandard ISO/IEC 15118.

The cost calculation station CH can communicate with further components,with the communication with the further components being indicated bydashed lines, which are only sometimes provided with reference symbolsK″, for reasons of clarity. The component OM in this case represents theoriginal manufacturer of the vehicle 1. The component MB relates to amobility operator, for example rental company of a fleet of vehicles towhich the vehicle 1 also belongs. Further value-added services of anydesired form are also provided via the component OS. The component UI isa user interface, for example a mobile telephone of the vehicle owner 1,via which information is transmitted to the vehicle owner from the costcalculation station. The component ER relates to one or more electricityretailers, via which current can be drawn as an alternative or inaddition to the energy supplier ES illustrated. The communication K″with the further components is not subject to the standardization inaccordance with standard ISO/IEC 15118. The communication between thecost calculation station CH and the charging station 2 or the furthercomponents is not essential to the method according to the invention,with the result that no further details are given regarding thesecommunication paths.

In the embodiment described here, a charging cable with a standard plug3 is used for charging the vehicle 1 at the charging station 2, saidplug having the design shown in plain view in FIG. 2. For the electricalsupply of the three-phase charging current, the plug contains the threepins L1, L2 and L3 and the neutral conductor pin N and the grounding pinG. Furthermore, the plug comprises a control pin P1, which is alsoreferred to as the pilot pin, and a further pin P2, which is used todetect, via an electrical resistance, whether or not the plug 3 has beenplugged into a corresponding socket 5 of the charging station. The plug3 can be locked in the socket 5 via a corresponding locking apparatus toprevent unauthorized removal, with the locking apparatus not being shownin the figures. Such a locking apparatus is known from the prior art andcan be realized, for example, by virtue of pins corresponding to thecharging station being removed from the socket for locking purposes andengaging in slots provided in the plug. The pins or slots can in thiscase be arranged at uniform distances along the outer circumference ofthe plug 3. In a preferred embodiment, three pins or slots arranged atan angle of 60° over the circumference of the plug are used.

Conventionally, the locking of the plug 3 in the socket 5 of thecharging station 2 is performed by the vehicle owner inputting acorresponding code at the charging station. The aim of the methodaccording to the invention is to bring about locking or unlocking on thebasis of the communication K between the vehicle 1 and the chargingstation 2. For this purpose, a suitable signal is transmitted from thecontrol unit CC of the vehicle to the control unit CC′ of the chargingstation, with the control unit CC′ triggering the locking or unlockingof the plug 3 in the socket 5 on reception of this signal.

FIG. 3 shows various variants for how the signal for locking orunlocking the plug 3 in the socket 5 can be performed. FIG. 3 shows aschematized illustration once again of the communication control unit CCon the side of the vehicle 1 and the communication control unit CC′ onthe side of the charging column 2. The communication control unit CC inthe vehicle communicates with further components in the vehicle whichare indicated by way of example by the block VC. These componentsinclude, inter alia, a charger for the battery of the vehicle and abattery management system. In the embodiment shown in FIG. 3, thecommunication control unit CC also communicates with the communicationcontrol unit CC′ of the charging station 2 via a first communicationconnection KV1. Furthermore, the communication control unit communicateswith the communication control unit CC′ via a second communicationconnection KV2, with a controller PPC interposed in the circuit on theside of the vehicle 1 and a controller PPC′ interposed in the circuit onthe side on the charging station 2. The communication connection KV2 isin this case the connection between the vehicle 1 and the chargingstation 2 which is produced via the pilot pin P1 of the plug 3. Thecommunication connection is managed via the controller PPC on the sideof the vehicle 1 and the controller PPC′ on the side of the chargingstation 2, with it being possible for the two controllers to also beinterpreted as part of the communication control units CC and CC′,respectively.

Conventionally, basic information which is required over the course ofthe charging operation is transmitted via the communication connectionKV2. The information transmitted is in particular information as towhether the plug has been plugged into a charging column (determined viathe pin P2), which charging mode from a specific number of chargingmodes has been selected and which state the vehicle is in. Furthermore,over the course of the communication via the connection KV2,identifications or authentication data, such as corresponding keys, forexample, can be transmitted, and these are then used for thecommunication described further below via the connection KV1 forauthorization or authentication of the vehicle 1 with respect to thecharging station 2.

In one variant of the method according to the invention, thecommunication connection KV2 is also used to signal that the plug 3 inthe charging station should be locked or unlocked. In one embodiment,this information can be provided, for example, by a change between thesignaled vehicle states “ready for charging” and “charging”. In theabove-described standard IEC 61851, Part 1, Annex A, correspondingvehicle states are already transmitted via the communication connectionKV2. These states include, in addition to the “ready for charging” and“charging” states, the state “disconnected”, which indicates that theplug is not connected to the charging station. The state “ready forcharging” in this case represents a state in which the charging of thebattery of the electric vehicle is possible, but the charging operationhas not yet been started. The state “charging” represents a chargingoperation of the battery of the electric vehicle which has beenperformed at that time. The state “disconnected” relates to a state inwhich the electric vehicle is not connected to the charging station. Thetransmission of information relating to these three states is performedin this case via pulse-width modulation, with the mentioned three statesbeing communicated from the vehicle to the charging station overcorresponding voltage levels on the positive half-cycle of thepulse-width-modulated signal. Furthermore, the information regarding thepower which is provided from the charging station for charging thebattery is transmitted to the vehicle via the pulse width from thecharging station. The three above-mentioned states are also defined inthe already adopted standard SAE J1772 for communication between avehicle and a charging station and can also be used, in the context ofthis standard, for signaling locking or unlocking of the plug of thecharging cable in the charging station.

In a preferred variant of the signal for locking or unlocking by meansof the states “ready for charging” and “charging”, locking of the plugis signaled by virtue of a change from the state “ready for charging” tothe state “charging”, whereupon the charging station locks the plug inthe socket. Unlocking can be signaled in a reverse manner by virtue of achange from the state “charging” to the state “ready for charging”,whereupon the charging station unlocks the plug. In this case othervariants of the signal for locking or unlocking the plug are alsoconceivable, for example a separate, dedicated control signal forlocking or unlocking can also be transmitted via the connection KV2.

In the exemplary embodiment shown in FIG. 3, the signal for locking orunlocking the plug can also be performed via the further illustratedcommunication connection KV1. This communication connection represents ahigher-order communication connection between the communication controlunits CC and CC′ as connection KV2. The connection KV1 can represent,for example, a PLC communication (power line communication) via apossibly also current-conducting line in the charging cable. There islikewise the possibility of a communication channel which is separatefrom the charging cable, for example radio transmission (in particularvia WLAN or Bluetooth) being used for data interchange. In particular,authentication of the vehicle 1 via the charging station 2 takes placevia the communication connection KV1, with the authentication datatransmitted via the communication connection KV2 being used for thispurpose as well. Further information for specific charging operationscan also be interchanged via the communication connection KV1, inparticular charging profiles, the state of charge of the battery andfurther control parameters. In the context of the invention, thiscommunication connection KV1 can also be used, if appropriate, forsignaling locking or unlocking of the plug in a suitable manner to thecharging station.

The transmission of the signal for locking or unlocking the plug can becoupled to various actions implemented in the vehicle. For example, thesignal can be coupled to the central locking of the vehicle, with theresult that the unlocking or locking of the plug is also signaled whenthe vehicle is opened or closed. There is likewise the possibility ofunlocking or locking being initiated explicitly by the vehicle user by aswitch in the vehicle, in analogy to a switch for locking or unlockingthe petrol flap of the vehicle. In general, the signal for locking orunlocking the plug can be transmitted in a manner coupled to a signalfor the charging operation, for example coupled with the signal for thestart and end of the charging operation or with the signal forapplication or safety-disconnection of the voltage to or from the plugcontacts of the plug 3. The signal for locking or unlocking can also betransmitted separately from a signal relating to the charging operation.

The method according to the invention described above has the advantagethat the locking or unlocking of a plug in the charging station can nowbe triggered remotely from the vehicle. It is thus no longer necessaryfor the driver of the vehicle to be authorized separately at thecharging station in order to trigger locking or unlocking of the plugvia a pin code, for example.

1. A communication method between an electric vehicle and a chargingstation, wherein, during a charging operation for electrically chargingthe electric vehicle, the electric vehicle is connected to the chargingstation via a lockable mechanical coupling between a terminal of acharging cable connected to the electric vehicle and a terminal of thecharging station, and charging current is supplied from the chargingstation to at least one energy storage device of the electric vehiclethrough the charging cable, the method comprising: transmittinginformation over a course of the charging operation for communicationbetween the electric vehicle and the charging station, the informationtransmitted from the electric vehicle to the charging station includinga signaling for unlocking the mechanical coupling, to thereby trigger inthe charging station an unlocking of the mechanical coupling between theterminal of the charging cable and the terminal of the charging station;using one or more of the following communication connections for thecommunication between the electric vehicle and the charging station: apower line communication (PLC) connection through one or morecurrent-conducting lines of the charging cable; a monitoring connectionthat is isolated from the current-conducting lines in the chargingcable; and a communication connection which is isolated from thecharging cable; representing states of the electric vehicle by one of aplurality of states, the states including a first state, whichrepresents that a connection through the charging cable between theelectric vehicle and the charging station is disconnected, and a secondstate, which represents that the at least one energy storage device ofthe electric vehicle is ready for charging via the charging cable andthe second state is indicated via one of the communication connections,with a change between the second and first states representing thesignaling by way of which the unlocking of the mechanical couplingbetween the terminal of the charging cable and the terminal of thecharging station is triggered.
 2. The method according to claim 1, whichcomprises coupling the signaling for unlocking the mechanical couplingto a signal relating to at least one of the charging operation or astate of charge of the energy storage device.
 3. The method according toclaim 2, which comprises coupling the signaling for unlocking themechanical coupling to a signal relating to at least one of a start ofthe charging operation, an end of the charging operation, an applicationand/or safety-disconnection of a voltage on the charging cable by thecharging station.
 4. The method according to claim 1, wherein thesignaling for unlocking the mechanical coupling is decoupled from asignal relating to the charging operation and to a signal relating to astate of charge of the at least one energy storage device of theelectric vehicle.
 5. The method according to claim 4, which comprisestransmitting authentication data for performing an authentication viathe monitoring connection in the charging cable, and then performing theauthentication via at least one of the PLC communication connection inthe charging cable or the communication connection that is isolated fromthe charging cable.
 6. The method according to claim 1, which comprisestransmitting the signal through a wireless communication connection. 7.The method according to claim 1, which comprises communicating by way ofthe information transmission via the PLC communication connection on apacket basis or the communication connection that is isolated from thecharging cable on a packet basis, and/or transmitting information viathe monitoring connection in the charging cable by way of pulse-widthmodulation or amplitude modulation.
 8. The method according to claim 1,wherein a change from the first state into the second state representsthe signaling via which a locking of the mechanical coupling between theterminal of the charging cable and the terminal of the charging stationis triggered.
 9. The method according to claim 8, which comprises, overthe course of the communication between the electric vehicle and thecharging station, performing an authentication of the electric vehiclewith respect to the charging station, and transmitting the signal forlocking the mechanical coupling from the electric vehicle to thecharging station only when authentication is successful.
 10. The methodaccording to claim 1, which comprises transmitting the signal forunlocking the mechanical coupling in response to an actuation of acentral locking of the electric vehicle.
 11. The method according toclaim 1, which comprises transmitting the signal for unlocking themechanical coupling in response to an actuation of a switch in theelectric vehicle.
 12. The method according to claim 1, which comprisesindicating the plurality of states via the monitoring connection.
 13. Asystem for communication between an electric vehicle and a chargingstation and electrically charging at least one energy storage device ofthe electric vehicle, wherein the electric vehicle is connected, duringa charging process, to the charging station via a lockable mechanicalcoupling between a terminal of a charging cable connected to theelectric vehicle and a terminal of the charging station in order tosupply charging current through the charging cable from the chargingstation to the at least one energy storage device, the systemcomprising: a first communication control unit for the electric vehicle;a second communication control unit for the charging station; at leastone communication connection for communication between said first andsecond communication control units selected from the group consistingof: a PLC communication connection through one or morecurrent-conducting lines of the charging cable; a monitoring connectionthat is isolated from current-conducting lines in the charging cable;and a communication connection that is isolated from the charging cable;with information being transmitted via the first and secondcommunication control units during operation of the system over thecourse of a charging operation based on a communication between theelectric vehicle and the charging station; said first and secondcommunication control units being configured such that the informationtransmitted therebetween includes signaling, generated by said firstcommunication control unit, for unlocking the mechanical coupling;wherein the electric vehicle is subject to a plurality of differentstates, the states including a first state, representing that thecharging cable between the charging station and the electric vehicle isdisconnected, and a second state, representing that the at least oneenergy storage device of the electric vehicle is ready for charging viathe charging cable and the second state is indicated via one of thecommunication connections, and wherein a change from the second state tothe first state triggers the unlocking of the mechanical couplingbetween the terminal of the charging cable and the terminal of thecharging station; and wherein said second communication control unit isconfigured to trigger the unlocking of the mechanical coupling betweenthe terminal of the charging cable and the terminal of the chargingstation via the signaling that indicates the change from the secondstate to the first state.
 14. The system according to claim 13, whereinthe system is configured to carry out and implement a method comprisingthe following steps: transmitting information over a course of thecharging operation for communication between the electric vehicle andthe charging station; thereby transmitting a signal from the electricvehicle to the charging station for unlocking the mechanical coupling,to thereby trigger in the charging station an unlocking of themechanical coupling between the terminal of the charging cable and theterminal of the charging station via the signal.
 15. An electricvehicle, comprising: at least one energy storage device; a connectionwherein the electric vehicle is connected, during a charging operation,to a charging station for electrically charging said at least one energystorage device by way of a lockable mechanical coupling between aterminal of a charging cable connected to the electric vehicle and aterminal of the charging station, whereupon charging current is suppliedfrom the charging station through the charging cable and to the at leastone energy storage device; a first communication control unit configuredto exchange information with a second communication control unit of thecharging station during a course of the charging operation on the basisof a communication between the electric vehicle and the charging stationvia at least one communication connection for communication between saidfirst and second communication control units selected from the groupconsisting of: a PLC communication connection through one or morecurrent-conducting lines of the charging cable; a monitoring connectionthat is isolated from current-conducting lines in the charging cable;and a communication connection that is isolated from the charging cable;wherein the electric vehicle is subject to a plurality of states, thestates including a first state, representing that the connection betweenthe charging station and the vehicle for electrically charging the atleast one energy storage device of the electric vehicle is disconnected,and a second state, representing that the at least one energy storagedevice of the electric vehicle is ready for charging via the chargingcable and the second state is indicated via one of the communicationconnections, and wherein a change from the second state to the firststate represents the signaling that triggers the unlocking of themechanical coupling between the terminal of the charging cable and theterminal of the charging station; and said first communication controlunit being configured such that the information transmitted between thefirst and second communication control unit includes the signaling,generated by said first communication control unit, for unlocking themechanical coupling via the signaling.
 16. The electric vehicleaccording to claim 15, wherein said communication control unit transmitsa signal indicating any of the plurality of states upon one or both ofan actuation of the central locking of the electric vehicle or a switchin the electric vehicle.
 17. A charging station for electricallycharging at least one energy storage device of an electric vehicle, thecharging station comprising: a charging station terminal for connection,via a lockable mechanical coupling, with a terminal of a charging cableconnected to the electric vehicle, wherein the electric vehicle isconnected via the lockable mechanical coupling in order to supplycharging current from the charging station to the at least one energystorage device during a charging operation; a second communicationcontrol unit configured to exchange information with a firstcommunication control unit of the electric vehicle over the course ofthe charging operation based on a communication between the electricvehicle and the charging station via at least one communicationconnection for communication between said first and second communicationcontrol units selected from the group consisting of: a PLC communicationconnection through one or more current-conducting lines of the chargingcable; a monitoring connection that is isolated from current-conductinglines in the charging cable; a communication connection that is isolatedfrom the charging cable; wherein the electric vehicle is subject to aplurality of states, the states include a first state, representing thatthe connection between the charging station and the vehicle forelectrically charging the at least one energy storage device of theelectric vehicle is disconnected, and a second state, representing thatthe at least one energy storage device of the electric vehicle is readyfor charging via the charging cable and the second state is indicatedvia one of the communication connections, and wherein a change from thesecond state to the first state represents a signaling that triggers theunlocking of the mechanical coupling between the terminal of thecharging cable and the terminal of the charging station; and said secondcommunication control unit being configured such that the informationtransmitted between the first and second communication control unitincludes the signaling, generated by said first communication controlunit, for unlocking the mechanical coupling via the signaling.
 18. Thecharging station according to claim 17, wherein said secondcommunication control unit is configured to selectively trigger anunlocking of the mechanical coupling between the terminal of thecharging cable and said terminal of the charging station upon receivinga predetermined signal transmitted from the electric vehicle to thecharging station.